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Welcome to the California Public Utilities Commission (CPUC) website for the California Environmental Quality Act (CEQA) review of San Diego Gas and Electric's (SDG&E’s) San Marcos to Escondido Tie Line (TL 6975) 69kV Project (proposed Project). An application for this project was submitted to the CPUC on November 15, 2017 (Application A.17-11-010). This site provides access to public documents and information relevant to the CEQA environmental review process.


SDG&E, in its CPUC application (A.17-11-010), filed on November 15, 2017, requests a Permit to Construct (PTC) the San Marcos-Escondido TL 6975 69kV Project.

The proposed project is subject to CEQA review because the CPUC has been presented with a discretionary action to approve or deny SDG&E’s PTC application. Before making a decision about SDG&E’s application, the CPUC is required to analyze potential environmental impacts associated with the project and present the findings in an environmental document for public review and comment. This website provides access to public documents and information relevant to the CEQA review process.

Project Overview

The proposed Project (see Location Map ) would occur in the cities of Carlsbad, Escondido, Vista and San Marcos, and in unincorporated  San Diego County, California.  Two auxiliary staging yards located in the city of San Diego are proposed for Project use. The proposed Project components at each location are summarized (by segment) below:

The proposed Project would include a combination of new overhead single-circuit electric power line structures, rebuild of existing structures from single circuit to double circuit, and the reconductoring and re-energizing of existing conductors.  The majority of the new build and reconductored portions of the power line would occur within existing rights-of-way (ROW)s. A portion of the Project (Segment 1 rebuild) would require the widening of existing ROW. 

The purpose of this proposed Project is to ensure the reliability of the transmission system, meet the State of California’s policy goals, accommodate load growth, and improve system efficiency in SDG&E’s service territory. SDG&E has identified the following objectives:

  1. Eliminate North American Electric Reliability Corporation (NERC) Category P0 (Cat A) and Category P1 (Cat B) violations on existing TL 684 (Escondido to San Marcos) and TL 680C (San Marcos- Melrose Tap) and;
  2. Meet mandatory NERC reliability criteria in the Escondido Area Load Pocket and alleviate the existing 69 kV congestion at the Escondido/ San Marcos Substations.   

Application and Proponent’s Environmental Assessment

On November 15, 2017, SDG&E filed an application (A.17-11-010) for a PTC which included a Proponent’s Environmental Assessment (PEA) for the proposed Project pursuant to Rule 2.4 of the CPUC's Rules of Practice and Procedure.

Environmental Review

The CPUC has prepared a Draft Mitigated Negative Declaration (Draft MND) to evaluate the environmental effects of the SDG&E San Marcos to Escondido Tie Line (TL)6975 69kV Project. The table below shows milestones and anticipated dates associated with the environmental review process.

Project Milestones as of October, 2020
Milestone Date
Application and PEA submitted by SDG&E November 15, 2017
CPUC PEA Deficiency Letter 1 December 15, 2017
SDG&E Response January 12, 2018
CPUC PEA Deficiency Letter 2 January 26, 2018
SDG&E Response February 28, 2018
Application and PEA - deemed complete March 16, 2018
Draft Initial Study/Mitigated Negative Declaration (Published) April 1, 2019
Public Comment Period April 1, 2019 – May 30, 2019
Public Meetings (2) April 30, 2019
Final Initial Study/Mitigated Negative Declaration (Published) January 10, 2020
Administrative Law Judge (ALJ) Proposed Decision August 5, 2020
CPUC Approval of Proposed Project September 24, 2020
Notice of Determination (NOD) posted September 25, 2020
CPUC Final Decision Issued October 5, 2020

Public Comment Period and Meetings

The Draft IS/MND was made available for a 60-day public and agency comment period, commencing on April 1, 2019, and ending May 30, 2019. The public, agencies, and interested parties presented comments and concerns regarding the Project and the adequacy of the Draft IS/MND. Comments were received through mailed letters, e-mail, comment cards, an on-line comment submittal tool, and petition, as well as through verbal comment recorded at the two public meetings (see below). These submitted comments will become part of the Project’s administrative record, which is public information, subject to disclosure under the California Public Records Act.

The CPUC conducted two public meetings to receive oral and written comments from the public, agencies, and interested parties.  The meetings were held as follows:

Tuesday, April 30, 2019
1:00 pm – 3:00 pm
San Elijo Recreation Center (Terrace Hall)
1105 Elfin Forest Road, San Marcos, CA 92069

Tuesday, April 30, 2019
6:00 pm – 8:00 pm
San Marcos Community Center (Main Hall)
3 Civic Center Drive, San Marcos, CA 92069

Copies of the public Draft IS/MND were made available for public review at these libraries during the comment period and remain available for informational purposes on this project website.

San Marcos Library
2 Civic Center Dr.
San Marcos, CA 92069

Escondido Public Library
239 S. Kalmia Street
Escondido, Ca 92025

Carlsbad City Library
1775 Dove Lane
Carlsbad, CA 92011

Documents Available for Review

Public documents related to the SDG&E Application for a Permit to Construct (PTC) and the PEA for the proposed San Marcos- Escondido Tie Line (TL6975) Project  can be found here:

CPUC Final Decision
Attachment A

ALJ Proposed Decision
Notice of Determination (NOD)

Final IS/MND
Final IS/MND Appendices

Public Draft IS/MND
Public Draft IS/MND Appendices
Notice of Intent (NOI) (April 1, 2019)

SDG&E PTC Application (A.17-11-010) (November 15, 2017)
Certificate of Service, Attachment 1 (November 15, 2017)
Proponent's Environmental Assessment PEA for TL6975 (November 15, 2017) (21.3 mb)
Letter of Completeness (March 16, 2018)

PEA Technical Appendices

PEA Appendix 3 Detailed Route Map, Structure Details, Agency Correspondence (November 15, 2017) (12.1 mb)
PEA Appendix 4.3 Air Quality (November 15, 2017) (986 kb)
PEA Appendix 4.4D Bio NCCP (November 15, 2017) (27.0 mb)
PEA Appendix 4.8-B Fire Plan (November 15, 2017) (2.56 mb)
PEA Appendix 4.12 Noise (November 15, 2017) (5.56 mb)

Data Requests, Responses and Attachments

CPUC PEA TL6975 Deficiency Letter 1 (December 15, 2017)

SDG&E Response TL6975 Deficiency Letter (January 12, 2018)
     Attachment 1 GIS shapefiles (no link)
     Attachment 2A SM Sub Plan Profile
     Attachment 2B ES Sub Plan Profile
     Attachment 3A Photo Points Map book
     Attachment 3B Existing Facilities
     Attachment 3C Visual Sims
     Attachment 4 NA Contact Program
     Attachment 5 Geotechnical Investigation

CPUC PEA TL6975 Deficiency Letter 2 (January 26, 2018)

SDG&E Response TL6975 Deficiency Letter 2 (February 28, 2018)
     Attachment 1 Load Forecast
     Attachment 2 Powerline Route Map
     Attachment 3A SM Sub Plan Profile
     Attachment 3B ES Sub Plan Profile
     Attachment 4 Power Flow Plots (confidential)
     Attachment 5 2017 Revised HCP
     Attachment 6 Herbicide Blend Recommendations
     Attachment 7A Cultural Resources Report Non-confidential
     Attachment 7B CR Report Supplemental Figures
     Attachment 8 Table of Databases
     Attachment 9 SDG&E Construction Water Sourcing Investigation Plan
     Attachment 10 SDG&E BMP Implementation Plan
     Attachment 11 VWD Will-Serve Letter

CPUC TL 6975 Data Request 1 (April 23, 2018)
SDG&E TL6975 Data Request 1 Responses - Cover Letter (May 15, 2018)
SDG&E TL6975 Data Request 1 Responses (May 15, 2018)
     Attachment 1 Record of GIS Data Received
     Attachment 2 Pole Inventory
     Attachment 3 SM Sub Plan Profile
     Attachment 4 Project Viewpoint Photos
     Attachment 5 TL 6975 Project CalEEMod
     Attachment 6 TL 6975 PEA Corrected Tables 3-10 and 3-13
     Attachment 7 Equipment and Haul Truck Trips per Phase

CPUC TL 6975 Data Request 2 and SDG&E Response (May 22, 2018)

CPUC TL 6975 Data Request 3 (June 28, 2018)
SDG&E TL6975 Data Request 3 Responses - Cover Letter (July 16, 2018)
SDG&E TL6975 Data Request 3 Responses (July 16, 2018)
     Attachment 1 AC Interference Analysis & Mitigation System Design
     Attachment 2 Traffic Control Mapbook

Historic Resource Inventory and Evaluation Report

CPUC TL6975 Data Request 4 (July 24, 2018)
SDG&E TL 6975 Data Request 4 Responses (August 7, 2018)
     Attachment 1 TL6975 SDG&E Helicopter Aviation Operations Manual
     Attachment 2 TL6975 SDG&E PEA Project Description Revisions

CPUC TL6975 Data Request 5 (October 30, 2018)
SDG&E TL 6975 Data Request 5 Responses (November 6, 2018)

CPUC TL6975 Data Request 6 (November 9, 2018)
SDG&E TL 6975 Data Request 6 Responses (November 21, 2018)
     Attachment 1 AC Mitigation Design GIS shapefiles (no link)
     Attachment 2 AC Mitigation Design GIS KMZ files (for Google Earth)

CPUC TL6975 Data Request 7 (January 4, 2019)
SDG&E TL 6975 Data Request 7 Responses (January 18, 2019)

CPUC TL6975 Data Request 8 (May 30, 2019)
SDG&E TL 6975 Data Request 8 Responses (June 9, 2019)
     TL6975 Escondido - Project Route Overview
     TL6975 San Diego County - Project Route Overview
     TL6975 San Marcos - Project Route Overview
     TL6975 San Marcos - Escondido Project - City of Escondido (April 15, 2019)
     TL6975 San Marcos - Escondido Project - County of San Diego (April 26, 2019)
     TL6975 San Marcos - Escondido Project - City of San Marcos (April 23, 2019)

CPUC TL6975 Data Request 9 (July 8, 2019)
SDG&E TL 6975 Data Request 9 Responses (July 9, 2019)

CPUC TL6975 Data Request 10 (July 29, 2019)
SDG&E TL 6975 Data Request 10 Responses (August 27, 2019)

CPUC TL6975 Data Request 11 (September 6, 2019)
     Item 1 - Photosimulation (September 18, 2019)
     Item 2a - Response Summary
     Item 2b - SDG & ELEHCP Summary Report (Amended August 8, 2019)
     Item 2c - SDG & ELEHCP Project Pending Post Construction Reports (Amended August 8, 2019)
     Item 3 - Appendix 3-A Mapbook

CPUC TL6975 Data Request 12 (October 17, 2019)
SDG&E TL6975 Data Request 12 Response
(October 24, 2019)

CPUC TL6975 Data Request 13 (October 23, 2019)
SDG&E TL6975 Data Request 13 Response (October 30, 2019)

For Additional Information

The CPUC, through its Environmental Review Team, is managing the environmental review of the Proposed Project. To request additional information, or to be added to the mailing list please contact us by email or phone, as follows:

Project email: TL6975SanMarcos@esassoc.com
Project voicemail: (619) 719-4207

The CPUC’s Project Manager is:

Lisa Orsaba
California Public Utilities Commission
Energy Division - Infrastructure Permitting & CEQA
505 Van Ness Avenue, 4th Floor
San Francisco, CA 94102
Tel.: (415) 703-1966

Formal Comment Mailing Address:

California Public Utilities Commission
Attn: San Marcos-Escondido TL6975

c/o David D. Davis, AICP
Environmental Science Associates
1425 N. McDowell Blvd. Ste. 200
Petaluma, CA 94954